<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
		<!-- 函数的递归调用：函数自己调用自己 
				- 递归时要设计结束条件
		 -->
		<script>
			var sum = 1;
			function fn1(a){
				sum = sum * a;
				a--
				if(a<=1){
					return;
				}
				fn1(a)
			}
			
			fn1(10)
			console.log(sum)
		</script>
	</body>
</html>
